“Love and Human Remains,” which opened last night at Playwrights Horizons, is the worst show we’ve ever not walked out of. But we almost did walk out during intermission by accident because we thought it might be the end. The storyline is really that murky; plus, the first act is an hour and a half, which is barbarically long, and it felt like it was time to go home. But we stayed.

The play is an adaptation of “Unidentified Human Remains and the True Nature of Love,” a title that's about as long as the show itself and twice as subtle. Originally a play in 1989, and then a movie in 1993, the show comes back to New York City after more than a decade and has smartly adopted the truncated movie title. Both versions of the script were penned by “Queer As Folk” writer Brad Fraser, and it shows. David (Zach McCoy), the prominently gay waiter-nee-actor (“Honey, I’m homo!” he exclaims), is the most realized character. Despite being in love with his straight best friend, Bernie (Nicholas Baroudi), when he meets 17-year-old virgin Kane (Paul Castro Jr.), it’s like “QAF” Season 1 all over again.

The play isn’t just about romance, as the title proves. As 30-something David and his anorexic bisexual roommate Candy (Kerri Lynn Miller, an appealing blend of Courtney Cox and Idina Menzel) try to figure out their love lives, there’s also a serial killer on the loose. This means that peripheral characters have to hang around and act as decoys. But the only red herring is the fact that one person is so obviously the killer that you have to think: “That CAN’T be the killer, right?” By the time the sadomasochistic psychic prostitute confirms that it is, we’ve already known for two hours. Oh, yes, there’s a magically intuitive junkie whore who reads auras and rapes minors. Benita (Frances Brennand Roper) is also our emcee; she lords over the plot and interjects with whimsical bits of song. Why not?

It’s not all bad: The set is just fine, while lights and sound were terrible. The directing (Clyde Baldo) is pretty bad — even though he directed it once before in 2002. The script is dated — like, this all could have been avoided with a smartphone. But there were definitely a few scenes so good that we wished they were in another play, all involving David and Candy; in the best sequence, her lovers, Jerri (Cassandra Paras) and Robert (Dan Almekinder), awkwardly share the same couch. The two roommates’ friendship is the heart of this show, and we just wish we could have seen it develop in a much cleaner story, rather than this overly convoluted non-mystery.